The invention concerns a knuckle joint hinge for furniture, having a supporting-wall part and a door part which are joined together by a knuckle joint mechanism formed by two link arms coupled pivotingly together in their central area, one of the extremities of one link arm being articulated to the supporting-wall part and one of the extremities of the other link arm being articulated to the door part, the other end in each case being guided along a curve in space and coupled to the other respective mounting part.
Knuckle joint hinges of this kind are increasingly used by furniture manufacturers because, by means of the knuckle joint mechanism, a motion can be realized which permits the door mounted on a carcase by such a hinge to open by 180.degree. even when another door directly adjoins it laterally, as for example in the case of built-in cabinets. The above-mentioned guidance of one end of each link arm along a curve in space can be accomplished either directly by guiding the link arm end in a cam track provided on the mounting part in question, or indirectly by means of an interposed link.
When a door mounted by a knuckle joint hinge swings from the closed to the open position, the link arms perform scissors-like swinging movements relative to one another and also movements relative to the mounting parts, whereupon gaps of varying size develop, especially between the doorside lever arms of the link arms, but also between the link arm closer to the door and the inside surface of the door. These size-varying gaps are hazardous in two ways. On the one hand, loose articles of clothing hung in the cabinet can be pinched in them and damaged, and on the other hand, children can accidentally get their fingers pinched and injured in them.
The invention is therefore addressed to the problem of improving the known knuckle joint hinges such that the above-mentioned injuries due to the pinching of fingers or the damaging of clothing will no longer be possible.
Setting out from the knuckle joint hinge of the initially mentioned kind, this problem is solved in accordance with the invention in that a filler piece is mounted for change of position in the area of the knuckle joint mechanism formed by the door-side lever arms of the link arms, which is urged by a biased spring into a position covering the variable gaps developing between the lever arms and the door in the opening and closing movement, and is supported at its extremity facing the door against the door or the door-related mounting part by means of a control cam. It has been found that there is sufficient space within the projection of the link arms for the accommodation of such a filler, which, if the control cam is appropriately shaped, will largely cover the variable gaps between the link arms and between the link arms and door in every closing or opening position.
If the knuckle joint hinge is, in a conventional manner, so constructed that the link arms each have two parallel sidewalls disposed in a spaced relationship to one another, it is recommended that the filler be disposed and mounted at least partially in the space formed between the parallel sidewalls, since the filler will then be virtually invisible.
If the filler is mounted between the sidewalls of the link arm articulated to the supporting-wall part and guided along a curve in space with the door part, and the coupling of the link arm to the door part is accomplished by means of a link, a recess is provided in the filler in the side facing the door, in further development of the invention, into which the link snaps when the hinge is approaching the closed position. The link thus does not limit the size of the profile of the filler, so that the lateral filler areas required for the covering of the hazardous gaps can be realized.
In a preferred embodiment of the invention, the filler is pivotingly mounted in or on the associated link arm and is biased by the spring in the sense of a swing toward the door. This pivoting mounting of the filler can be accomplished quite simply by means of a pin passed through aligned bores in the sidewalls of the link arm and in the filler.
If the two sidewalls of the link arm accommodating the filler between them are closed at their sides facing away from the door by a spanning portion forming a U-shaped profile in cross section, the spring biasing the filler is constructed preferably as a compression spring thrusting at one end against the inside of the spanning portion and at the other end against or inside the filler.
In an alternative embodiment of the invention, the filler can also be guided by a cam and can be held by the cam for pivoting in or on the associated link arm, in which case it is then also coupled to the link arm by a filler link. By means of this slightly more complex mounting of the filler, the hazardous spaces between the link arms can be covered to a slightly greater extent than in the case of a merely pivotal linking of the filler.
The filler link is mounted at the link arm end preferably on the pintle coupling the link arms together in their central area to form the knuckle joint mechanism, i.e., no separate pin is required for this end of the filler link.
Since the filler link enters a recess in the filler and therefore the space available for the accommodation of a compression spring is limited, it is then recommendable to construct the spring as a tension spring whose one end is attached to the filler link adjacent its pivot at the filler end of the latter, and whose other end is attached to the supporting-wall part of the hinge.
For the sake of simple and economical manufacture, the filler is made of plastic, as is also, if desired, the filler link.